A generic device is known from document DE 43 02 783 A1 in which the connecting bars are pushed between first and second busbars to be connected, which busbars oppose each other at their ends, and are then connected by a single connecting bolt to the first and second busbars. In the process the connecting bolt penetrates the connecting bars in the region of a first through-opening. Third busbars are also provided in this known device, which are to be connected to the first and second busbars and have a recess that is open on one side to embrace a second connecting bolt which penetrates the connecting bars in the region of a second through-opening. In the process the third busbars extend parallel to the butt joint which is formed between the end faces of the first and second busbars.
However, in practice busbars are pre-assembled in segments in order to be connected later at the place of use. This is the case, by way of example, in wind turbines or on ships.
Document DE 101 52 557 C1, by way of example, therefore discloses a wind turbine with a tower constructed from a plurality of tower segments, with a generator arranged in the region of the tower head, with a power module arranged in the region of the tower base and with current conduction device(s) for transmitting current from the generator to the power module. The electrical power module in this wind turbine, which includes the electrical units, such as transformer, switch panels, optionally rectifiers, medium voltage electrical installations, low voltage distribution, etc. is arranged below the generator level in the region of the tower base of the wind turbine.
Current conduction device(s), which extend inside the tower, are provided to transmit the electrical energy generated by the generator arranged inside the nacelle in the region of the top of the tower to the power module. These current conduction device(s) include busbars pre-assembled in the individual tower segments and which are connected in the region of the joints of the individual tower segments with the aid of flexible connecting bars. Prefabricated busbar segments are therefore preferably provided on the tower segments before the tower is erected from the individual tower segments, and the busbar segments are connected with the aid of the flexible connecting bars following erection of the tower.
It is no longer necessary to laboriously pull cables through the tower following its erection in order to electrically connect together generator and power module. The total wind turbine erection time can consequently be reduced and the costs of erection lowered without any technical drawbacks having to be accepted. Connection of the flexible connecting bars to the pre-assembled busbar segments is still laborious, however, as the individual phase conductors of the busbars have to be individually connected to associated phase conductors of the flexible connecting bars.
It is also known from document DE 101 45 414 A1 that the power module of a wind turbine is mounted on a tower base before erection of the tower. The illustrated power module is firstly set on a supporting plate. It consists of two power module segments which are placed one above the other and comprises supports which hold essential parts of the power module, i.e. for example the transformer, rectifier, switch panels, medium voltage electrical installation, etc. The supports placed one above the other are constructed in the manner of a frame and fit exactly one above the other, so reliable securing against each other is also ensured. The individual supports comprise struts inter alia that are connected to each other.
Once the electrical power module has been placed on the base the tower is erected and placed over the power module in the process. The external dimensions of the power module in relation to width and length are smaller than the internal diameter of the tower in the bottom region of the tower/base region. Once the tower has been erected the wind turbine is fitted with the nacelle as is customary, the rotor is mounted and appropriate electrical connections are made between the generator and the power module for commissioning and the power module (output of the transformer) is also connected to the power supply system. In practice the individual phase conductors of the power module segments have previously been laboriously connected with the aid of flexible intermediate pieces (cables) which are connected to the phase conductors with the aid of a screw connection.
It is desirable both when assembling the tower segments one above the other and when assembling the power module segments one above the other, but, for example, also when placing ship's containers or mobile homes next to each other for the busbars pre-assembled in the segments or containers to not project beyond the external dimensions of the respective segment/container to prevent damage to the busbars when joining the segments/containers together.